By Julie Glass

It took almost two hours of scoreless soccer before last night’s U.S. Open Cup game  between the Union and D.C. United erupted with a flurry of goals — and eventually Wayne Rooney’s game-winning penalty kick in the final minute of extra time.

United won, 2-1, advancing to the round of 16 over a shorthanded Union squad.

All three of the game’s goals came in the final seven minutes of extra time, beginning with Anthony Fontana’s score for the Union in the 113th minute of play. D.C. responded, with Chris McCann’s header off Rooney’s corner in the 118th minute. Then, after Luciano Acosta drew a foul in the penalty box, Rooney blasted the ball into the net soon after to keep the game from extending further into penalty kicks.

The Open Cup, a knockout tournament in American soccer, features both professional and amateur teams, but MLS clubs do not enter until the fourth round, when 32 squads remain.

Both teams used backup goalkeepers in the matchup. Philly was without Andre Blake, who’s with the Jamaican national team that recently beat the United States in a friendly at Audi Field, while United’s Bill Hamid missed the game for precautionary reasons like Canouse. Chris Seitz, United’s backup goalkeeper, played a mostly mistake-free game, finishing with five saves against a Philadelphia attack that produced 24 shots.

Olsen called United’s start passive. The team took just four shots in the first half with none on goal compared with the Union’s 13 shots with three on goal in the opening 45 minutes of play. But eventually, even if only in the waning moments, United prevailed to move forward in the tournament.

“They just had a better mentality from the get-go, and then we got into the game, and it became important to us,” Olsen said. “But it took a little bit.”